Hydrogenated TiO2 Carbon Support for PtRu Anode Catalyst in High-Performance Anion-Exchange Membrane Fuel Cells.

The availability of durable, high-performance electrocatalysts for the hydrogen oxidation reaction (HOR) is currently a constraint for anion-exchange membrane fuel cells (AEMFCs). Herein, a rapid microwave-assisted synthesis method is used to develop a core-shell catalyst support based on a hydrogenated TiO2 /carbon for PtRu nanoparticles (NPs). The hydrogenated TiO2 provides a strong metal-support interaction with the PtRu NPs, which improves the catalyst's oxophilicity and HOR activity compared to commercial PtRu/C and enables greater size control of the catalyst NPs. The as-synthesized PtRu/TiO2 /C-400 electrocatalyst exhibits respectable performance in an AEMFC operated at 80 °C, yielding the highest current density (up to 3× higher) within the catalytic region (compared at 0.80-0.90 V) and voltage efficiency (68%@ 0.5 A cm-2 ) values in the compared literature. In addition, the cell demonstrates promising short-term voltage stability with a minor voltage decay of 1.5 mV h-1 . This "first-of-its-kind in alkaline" work may open further research avenues to develop rapid synthesis methods to prepare advanced core-shell metal-oxide/carbon supports for electrocatalysts for use in the next-generation of AEMFCs with potential applicability to the broader electrochemical systems research community.

Nuclear plasticity increases susceptibility to damage during confined migration.

Large nuclear deformations during migration through confined spaces have been associated with nuclear membrane rupture and DNA damage. However, the stresses associated with nuclear damage remain unclear. Here, using a quasi-static plane strain finite element model, we map evolution of nuclear shape and stresses during confined migration of a cell through a deformable matrix. Plastic deformation of the nucleus observed for a cell with stiff nucleus transiting through a stiffer matrix lowered nuclear stresses, but also led to kinking of the nuclear membrane. In line with model predictions, transwell migration experiments with fibrosarcoma cells showed that while nuclear softening increased invasiveness, nuclear stiffening led to plastic deformation and higher levels of DNA damage. In addition to highlighting the advantage of nuclear softening during confined migration, our results suggest that plastic deformations of the nucleus during transit through stiff tissues may lead to bending-induced nuclear membrane disruption and subsequent DNA damage.

Improved nutrient use efficiency increases plant growth of rice with the use of IAA-overproducing strains of endophytic Burkholderia cepacia strain RRE25.

Effect of indole acetic acid (IAA)-overproducing mutants of Burkholderia cepacia (RRE25), a member of ß-subclass of Proteobacteria and naturally occurring rice endophyte, was observed on the growth of rice (Oryza sativa L.) plants grown under greenhouse conditions. Nine mutants were characterized for altered biosynthesis of IAA after nitrous acid mutagenesis. These mutants were grouped into two classes: class I mutants have reduced production of IAA as compared to the wild type, while class II mutants showed overproduction of IAA. Mutants of both classes and RRE25, the parent (wild type), were inoculated on rice seedlings of two cultivars (Sarjoo-52 and NDR-97). Uptake of nitrogen, phosphorous, and potassium was estimated in these plants. Significant increase in the amount of uptake of all three elements was observed when inoculated with the IAA-overproducing mutants over control as well as in the plants inoculated with the wild type (RRE25). Effect of inoculation of IAA-overproducing mutants was more pronounced on the uptake of phosphorous in cultivar NDR-97 than Sarjoo-52, while it was opposite with respect to potassium uptake. Any significant difference was not observed in nitrogen uptake among the two cultivars. It shows that the host also plays an important role in the beneficial endophytic association. It was concluded from these results that one of the possible mechanisms of growth promotion of rice plants inoculated with bacterial endophytes is their effects on an increase in the capability of nutritional uptake possible through the effect of IAA production which results in proliferation of root system that could mine more nutrients from the soil.

Elucidation of diversity among F1 hybrids to examine heterosis and genetic inheritance for horticultural traits and ToLCV resistance in tomato.

Genetic diversity during prebreeding or postbreeding programme, is the key pillar to characterize the valuable traits and gene of interest. Whereas, superior or inferior heterotic performance of F1 depend on the diverse nature of their pedigree. Therefore, the aim of this study was to see the diversity between the interspecific crosses and effect of heterosis, and inheritance for the morphological traits and ToLCV resistance. All the 24 F1 interspecific crosses were classified into four clusters on the basis of morphological traitsas well as simple sequence repeat (SSR) markers. Among the F1 hybrids, 23 were grouped into clusters II, III and IV with different phylogeny, while PBC×EC 521080 was individual with cluster I. On the basis of visual observation of fruit colour, deep red and green colours in the crosses of S. pimpinellifolium (EC 521080) and S. habrochaites (EC 520061) exhibited dominant effects. In context of heterosis breeding, the crosses which were made using Solanum pimpinellifolium (EC 521080), S. chmielewskii (EC 520049) and S.cerasiforme (EC 528372) were better for yield capacity and the crosses of S. habrochaites (EC 520061) exhibited low and negative heterosis for ToLCV resistance. The F1 progenies were segregated in various Mendelian ratio as follows 3:1, 1:2:1, 1:3, 13:3, 15:1, 12:3:1 and 9:6:1 for ToLCV disease reaction of incidence, plant growth habit and fruit colour appearance, respectively. Therefore, these interspecific crosses can be utilized for developing high yield, impressive fruit colour combiners and resistant hybrids/varieties of tomato.

Genetic analysis to identify good combiners for ToLCV resistance and yield components in tomato using interspecific hybridization.

The interspecific hybridization for tomato leaf curl virus (ToLCV) resistance was carried out among 10 genetically diverse tomato genotypes (diversified by 50 SSR markers). Among the 10 parents, four susceptible cultivars of Solanum lycopersicum were crossed with six resistant wilds, such as S. pimpinellifolium, S. habrochaites, S. chemielewskii, S. ceraseforme, S. peruvianum and S. chilense in a line x tester mating design. All the 24 hybrids and their parents were grown in the field and glasshouse conditions to determine the general-combining abilities (GCA) and specific-combining abilities (SCA). The variances due to SCA and GCA showed both additive and nonadditive gene effects. Based on GCA estimates, EC-520061 and WIR-5032 were good general combiners while based on SCA estimates, PBC x EC-520061 and PBC x EC-521080 were best specific combiners for coefficient of infection and fruit yield per plant in both the environments. These lines could be selected and utilized in ToLCV resistance and high yield breeding programme for improving the traits.

Rhizobium-mediated induction of phenolics and plant growth promotion in rice (Oryza sativa L.).

Qualitative and quantitative estimation of phenolic compounds was done through reverse phase-high performance liquid chromatography (RP-HPLC) from different parts (leaf, stem, and root) of rice plants after inoculation with two rhizobial strains, RRE6 (Rhizobium leguminosarum bv. phaseoli) and ANU 843 (R. leguminosarum bv. trifolii) and infection by Rhizoctonia solani. On the basis of their retention time, the major phenolic acids detected in HPLC analysis were gallic, tannic, ferulic, and cinnamic acids. Furthermore, in all Rhizobium-inoculated rice plants, synthesis of phenolic compounds was more consistently enhanced than in control (uninoculated plants), where the maximum accumulation of phenolic compounds was observed in plants inoculated with RRE6 and infection with R. solani. Under pathogenic stress, RRE6 performed better because a relatively higher amount of phenolics was induced as compared with plants treated with ANU 843. Phenolic acids mediate induced systemic resistance and provide bioprotection to plants during pathogenic stresses. In addition, both rhizobial strains promote growth and productivity of rice plants in greenhouse conditions. This report on Rhizobium-mediated defense responses and growth promotion of nonlegume (such as rice) provides a novel paradigm of symbiotic plant-microbe interaction.

Isolation and identification of natural endophytic rhizobia from rice (Oryza sativa L.) through rDNA PCR-RFLP and sequence analysis.

Three novel endophytic rhizobial strains (RRE3, RRE5, and RRE6) were isolated from naturally growing surface sterilized rice roots. These isolates had the ability to nodulate common bean (Phaseolus vulgaris). Polymerase chain reaction-restriction fragment length polymorphism and sequencing of 16S rDNA of these isolates revealed that RRE3 and RRE5 are phylogenetically very close to Burkholderia cepacia complex, whereas RRE6 has affinity with Rhizobium leguminosarum bv. phaseoli. Plant infection test using gusA reporter gene tagged construct of these isolates indicated that bacterial cells can go inside and colonize the rice root interiors. A significant increase in biomass and grain yield was also recorded in greenhouse-grown rice plants inoculated with these isolates.

Isolation and identification of natural endophytic rhizobia from rice (Oryza sativa L.) through rDNA PCR-RFLP and sequence analysis.

Three novel endophytic rhizobial strains (RRE3, RRE5, and RRE6) were isolated from naturally growing surface-sterilized rice roots. These isolates had the ability to nodulate common bean (Phaseolus vulgaris). Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and sequencing of 16S rDNA of these isolates revealed that RRE3 and RRE5 are phylogenetically very close to Burkholderia cepacia complex, whereas RRE6 has affinity with Rhizobium leguminosarum bv. phaseoli. Plant infection test using gusA reporter gene-tagged construct of these isolates indicated that bacterial cells can go inside and colonize the rice root interiors. A significant increase in biomass and grain yield was also recorded in greenhouse-grown rice plants inoculated with these isolates.